Microtome tool holder



FIG. 1 is a perspective view of a microtome tool holder showing my new design;

FIG. 2 is a left side elevational view;

FIG. 3 is a front elevational view;

FIG. 4 is a top plan view; and,

FIG. 5 is a rear elevational view thereof. 

The ornamental design for a microtome tool holder, as shown. 